1. Field of the Invention
The present invention is directed to an obstruction lamp which is LED illuminated. Such an LED obstruction lamp may find use in and around airports, and may be placed on the top of jet blast fences, runway edges, towers, mountains, tall buildings, etc.
2. Discussion of the Background
Currently, obstruction lamps utilized in and around airports utilize incandescent or fluorescent elements. Incandescent and fluorescent obstruction lamps are currently utilized because they meet FAA requirements. The U.S. Department of Transportation Advisory Circular 150/5345-43 specifies the requirements for obstruction lighting equipment. Of particular interest with respect to that Circular are the requirements for relamping, salt fog resistance, operating temperature range, and light intensity.
Incandescent obstruction lamps suffer from at least three significant drawbacks. A first drawback is that incandescent light bulbs are relatively inefficient, and thus use a large amount of power. A second drawback with incandescent obstruction lamps is that the incandescent light bulbs typically burn out within twelve to eighteen months. That is a particular drawback because obstruction lamps are typically placed over a large area in and around airports, and further are placed at locations which may be quite difficult and dangerous to reach. That is, obstruction lamps must be placed on the top of towers, on mountains, on tall buildings, etc. Due to the location of obstruction lamps, the replacement of burned out obstruction lamps can be very difficult and costly. A third drawback is that vibration of obstruction lamp modules can be quite extensive when mounted in certain locations, such as jet blast fences. That vibration can cause delicate lamp filaments in incandescent elements to break prematurely.
Accordingly, one object of the present invention is to provide a novel, long life, obstruction lamp for use in and around airports which can reduce maintenance costs, and particularly with respect to the costs associated with replacing burned out obstruction lamps.
A further object of the present invention is to provide a novel obstruction lamp with improved energy efficiency.
A further object of the present invention is to provide a novel obstruction lamp which can meet all appropriate FAA requirements, and in particular temperature and relamping.
A further object of the present invention is to provide a novel obstruction lamp which can be retrofitted onto existing obstruction lamp housings.
A further object of the present invention is to provide a novel obstruction lamp which is sealed against moisture and which is protected during handling.
To achieve the above and other objects, the present invention sets forth a novel obstruction lamp which replaces conventional incandescent obstruction lamps and which utilizes light emitting diodes (LEDs) in the illumination unit. The novel obstruction lamp of the present invention includes a first plurality of LEDs connected in series. The first plurality of LEDs are mounted onto a metal vertical cylinder, which provides a heat sinking for the first plurality of LEDs. A lens, with suitable optics, is configured to cover the first plurality of LEDs and the metal vertical cylinder. A metal base is provided on which the metal vertical cylinder, the lens, and signal conditioning circuitry are mounted. Further, a clamp is configured to attach and seal the lens to the metal base.
As a further feature of the novel obstruction lamp of the present invention, a second plurality of LEDs may be connected electrically independently of the first plurality of LEDs and mounted on top of the metal vertical cylinder to provide an improved aesthetic appearance.
As a further feature of the novel obstruction lamp of the present invention, a housing to enclose wire interconnections may be configured to attach to the metal base.
As a further feature of the novel obstruction lamp of the present invention, an adapter may be configured to attach between the metal base of the obstruction lamp and the base of a previously installed incandescent lamp.
As a further feature of the novel obstruction lamp of the present invention, the metal vertical cylinder can include driving circuit boards configured to drive the first and/or second plurality of LEDs.
As a further feature of the novel obstruction lamp of the present invention, the first plurality of LEDs may be high power LEDs and the second plurality of LEDs may be lower power LEDs which are provided more for aesthetic purposes than for providing needed light output.